Spinlock.h

/*
 * Copyright (c) 2008-2014, Pedigree Developers
 *
 * Please see the CONTRIB file in the root of the source tree for a full
 * list of contributors.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#ifndef KERNEL_SPINLOCK_H
#define KERNEL_SPINLOCK_H

#include "pedigree/kernel/Atomic.h"
#include "pedigree/kernel/compiler.h"
#include "pedigree/kernel/processor/types.h"

class EXPORTED_PUBLIC Spinlock
{
    friend class PerProcessorScheduler;
    friend class LocksCommand;

  public:
    Spinlock();
    Spinlock(bool bLocked, bool bAvoidTracking = false);

    bool acquire(bool recurse = false, bool safe = true);

    void exit();

    void release();

    bool acquired();

    bool interrupts() const;

    static const bool allow_recursion = true;

  private:
    void unwind();

    void trackRelease() const;

    volatile bool m_bInterrupts = false;
    Atomic<bool> m_Atom = true;  // unlocked by default
    Atomic<uint64_t> m_CpuState = 0;

    uint64_t m_Sentinel = 0;

    uint32_t m_Magic = 0xdeadbaba;
    uint32_t m_MagicAlign = 0;

    void *m_pOwner = nullptr;
    size_t m_Level = 0;
    size_t m_OwnedProcessor = ~0;

    uintptr_t m_Ra = 0;

    bool m_bAvoidTracking = false;
    bool m_bOwned = false;
};

#endif